The Villans could not find a way through on Humberside, making it just one point collected from the last nine on offer in the Championship.
A failure to break down the struggling visitors leaves Villa nine points adrift of second-placed Cardiff City, having played a game more than the Welsh outfit.
Adomah was then wayward with a chance from closer range, poking the ball over the bar from a great position, before Jack Grealish sent one wide of the post from 18 yards.
Villa started to assert their authority on the game a little more, with Grealish driving his latest shot into the arms of McGregor, who also did well to keep out a curler from Robert Snodgrass.
Another chance went begging for the visitors prior to half time when John Terry diverted a corner onto the roof of the net, as the teams somehow went into the break on level terms.
Hull felt that they should have had a penalty early in the second period after Grealish raised his arms to block a free kick, while Jon Toral had an appeal of his own turned down following an infringement from Alan Hutton.
Villa were lacking the clinical edge in the second period and could well have been behind when the ball fell to the feet of Toral, who blasted his chance over the bar from inside the area.
Terry squandered another half-chance late on as a Hull side six points clear of the dropzone held out for a share of the spoils, making it just one home loss in 11.
HULL CITY (4-2-3-1): McGregor; Aina, Dawson, MacDonald (Hector 66'), Clark; Larsson, Henriksen; Bowen, Irvine (Toral 59'), Wilson (Grosicki 77'); Hernandez
ASTON VILLA (4-1-4-1): Johnstone; Tuanzebe (Elmohamady 75'), Chester, Terry, Hutton; Jedinak (Kodjia 62'); Lansbury, Adomah (Hogan 83'), Snodgrass, Grealish; Grabban